On Tue, May 12, 2015 at 12:17:29AM +0200, Sjoerd Simons wrote:
> The L2C cache should only be unlocked when the cache is setup to allow
> that. In the common case the l2x0 driver sets up the cache for that to
> be the case (e.g. setting L310_AUX_CTRL_NS_LOCKDOWN on L2C-310), making
> unlock safe. However when a secure firmware is in use, it may not be
> possible for the L2c to be configured that way making unlocking unsafe.
>
> To handle that case add a flag to skip unlocking the cache for machine
> where this can't be done safely.
>
> Signed-off-by: Sjoerd Simons <[email protected]>
> ---
> arch/arm/include/asm/outercache.h | 1 +
> arch/arm/mm/cache-l2x0.c | 4 +++-
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/include/asm/outercache.h
> b/arch/arm/include/asm/outercache.h
> index 563b92f..d07ca82 100644
> --- a/arch/arm/include/asm/outercache.h
> +++ b/arch/arm/include/asm/outercache.h
> @@ -39,6 +39,7 @@ struct outer_cache_fns {
> /* This is an ARM L2C thing */
> void (*write_sec)(unsigned long, unsigned);
> void (*configure)(const struct l2x0_regs *);
> + bool skip_unlock;
> };
>
> extern struct outer_cache_fns outer_cache;
> diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
> index e309c8f..fff7888 100644
> --- a/arch/arm/mm/cache-l2x0.c
> +++ b/arch/arm/mm/cache-l2x0.c
> @@ -136,7 +136,8 @@ static void l2c_enable(void __iomem *base, u32 aux,
> unsigned num_lock)
> l2x0_saved_regs.aux_ctrl = aux;
> l2c_configure(base);
>
> - l2c_unlock(base, num_lock);
> + if (!outer_cache.skip_unlock)
> + l2c_unlock(base, num_lock);
I think we can do better here. If the non-secure lockdown access bit has
been set, then proceed with the unlock:
if (readl_relaxed(base + L2X0_AUX_CTRL) & L310_AUX_CTRL_NS_LOCKDOWN)
l2c_unlock(base, num_lock);
I don't see any need to add a flag for this. This also eliminates your
second patch.
--
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
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